Field of the Invention
The present invention relates to an image recognition apparatus for recognizing an object included in an image, and its control method and program.
Description of the Related Art
In recent years, an image pickup apparatus having an object recognition function for recognizing a specific object included in an image is proposed. With the object recognition function, a focus and an exposure can be preferentially controlled for the recognized object. The image pickup apparatus having the object recognition function detects an object area including the object from an image obtained by a photographing and extracts feature information for discriminating the object area as a recognition target from the image of the detected object area. The extracted feature information is compared with feature information of registered objects which have previously been registered as dictionary data and, on the basis of a degree of similarity obtained by the comparison, which registered object the object of a recognition target is or whether or not the relevant registered object exists is recognized. Such a system that a person's face is detected as an object area, feature information of the detected face is extracted, and whose face is the detected face is determined, thereby performing a personal recognition is disclosed (for example, refer to the Official Gazette 1 of Japanese Patent Application Laid-Open No. 2003-187352). In the Description, with respect to an image such as a detected face or the like, a processing for discriminating whose (which) face such an image corresponds is referred to as “recognition”.
For example, in the case of detecting a face as an object area, an accuracy of such an object recognition as mentioned above is influenced by a state such as an expression or orientation of the face area. Therefore, if a state of the face area of the recognition target differs from a state of the face area registered as dictionary data, there is a case where an accuracy of the personal recognition deteriorates. Therefore, there is a case where a result of the accurate personal recognition cannot be expected depending on the state of the face area of the recognition target. In a case where the image pickup apparatus has an image pickup unit which supplies images picked up sequentially in time series, if a state where which registered object the recognition target is confirmed is successively maintained between images by using an object tracking technique, a recognition confirmed state can be stably maintained. However, if a failure in tracking occurs in the object tracking, the recognition confirmed state is successively maintained to a different object, so that the apparatus will be in a state where such a different object is recognized as a registered object.